Recent retrospective studies suggested that early postoperative infections might be associated with a survival benefit for extremity osteosarcoma patients, but the reported results have been conflicting. The files of 437 patients with a newly diagnosed, high-grade osteosarcoma of the extremities treated at 5 referral centers in Germany and Austria between 1989 and 2016 were retrospectively evaluated. All patients underwent multi-agent chemotherapy and limb-sparing tumor excision, followed by endoprothetic replacement. We used the Kaplan-Meier method to calculate survival curves, which we compared with the log-rank test. With a median follow-up of 100 months (interquartile range, 49-155 months), local recurrence (LR) probability, event-free survival (EFS), and disease-specific survival (DSS) after 5 years in this selected patient cohort amounted to 5%, 67%, and 79%, respectively, and 46 patients (10.5%) developed an early postoperative infection. We found no significant differences in LR, EFS, or DSS between patients with and without early infections, and there were no differences in known prognostic factors between the two groups. However, in subgroup analyses patients with a poor response to neoadjuvant chemotherapy and an early infection had a better DSS compared to patients without early infections (93% vs. 62% after 5 years, p = 0.044). Provided that our findings can be validated in separate patient cohorts, we believe that patient outcome after adjuvant immunomodulatory treatments in osteosarcoma patients should be evaluated and reported separately for good and poor responders to neoadjuvant chemotherapy in future studies.
Keywords: immunomodulatory treatments; osteosarcoma; patient survival; postoperative infection; response to chemotherapy.